Combination lock



Nov. 8, 1955 M. E. 'COFFEY 2,722,820

COMBINATION LOCK 2 Sheets-Sheet 1 Filed May 21, 1954 INVENTOR. MENDEL.E. Co FFEY fizf-mmazqpmm WWW ATTORNEYS Nov. 8, 1955 M. E. COFFEY2,722,820

COMBINATION LOCK Filed y 21, 1954 2 Sheets-Sheet 2 Fig.4

IN VEN TOR. MENDEL. E. -COFFEY Q8 BY wwnazqjmm 0mm ATTQQMEY UnitedStates Patent O "ice This invention: relates to a: combination :lock andu more particularly toca lock of the type having ,tumblerwheels and acamdisk" mounted ftotrotatevtabout a qcommonyaxis, Theprimary' object ofthe invention is vto frustratetheeunlocking of i the lockgby' detectionof .the passage of the notches which open through the'peripheries of thetumbler wheels and'therecess whichopensthrough the periphery of the camdisk beneath ,thefenceandzthe operating lever of the lock;

Another object is to interpose' between the recessed periphery of thecam disk and the cam' follower tongue; of a conventional lock arim'guard on the surface of, which the cam follower tongue ;rides duringthe manipu lation of the lock.

Another object is to disengagezthe'rim guard from'thecam diskwhen. thecombinationhasjb'een.set upfto permit the entrance of the cam-followertongue; into the notch of the camrdisk toreleasethe lock bolt.

The above and otherobjects may be 'attainedsvby employing/this inventionwhich embodies amongitsfeatures a-rirn guard mounted adjacent the camtdiskgf'orcmovemerit longitudinally relative thereto fromian-v activeposition in s which? ,it encircles the camwdiskand engageszthe carnfollower tongue ofthehlock to an-inactive;position inwwhichzitlies: toone sideof the camdisloandwutof:

the path of advance of the cam follower tongue.

Other. features include a push? rod mounted-int the lock? for movementlongitudinally along-theaxis ofthe" cam disk; an annular:rim guardcarried by the'push; rod; for movement therewith adjacent-thecamldisk=andmeanscarried by the. lock; and operatively engagingythewpush"rod for yieldingly advancing theannular.rim-guardunderyielding pressureinto earn disk encirclingt relation; and means: operable from'the frontof the lock and operatively connectedto the, rim' guard forr-movinggit'against:

the'yielding pressure out ofthe path-of advance ofthe cam" followertongue to permit thetongue to; enter. the:

recess in the cam disk to operatively connect the-operating lever tothecam disk for movemenbof the bolt.

Still otherrfeatures include bevelingthe periphery: of

the annular: guard 'rirn to facilitatetheientrance-thereof between thecam disk and thecamfollower tongue under theiiniluence of the yielding.pressure, astop ipin carried by-the locktand extending into thepath ofmovement of the rim guard-"when the latter is moved. against the effortof the:yielding-:pressure, and saidrim guard having a sloti extendingtherethrough for receiving the: stop pinito .limit the rotation: of thecam guard when it is-movediout of thepath of advancenf the camfollowerwtongue;

Still other featuresinclude serrations on-the;:surfaces--v ofthe;tumbler wheels, andserrations'on: the jfencenfori cooperating withthe serrationson thesurfacesoftthe.

tumblenwheels-to frustrate'any sense of afeel being transmitted to theknob by which the tumbler wheels andhcamn diskarerotatedfl In thedrawings: Figure liis aperspectiveviewtof a combination lock embodyingthe features of this invention;

Figurex2eis awlongitudinal sectional view taken substantially on theline 22 of Figure :1;

Figure 3 -isi a' longitudinal sectional view taken substantiallyon .theline 3-3 of Figure 1;

Figure 4 is a longitudinal sectional view taken substantiallyon-the line4.4of Figure 1 FigureSis a view similar. to Figure 2, showing the boltretracted;

Figure-"6 is a horizontal sectional view taken substantially .on theline 66' of Figure :5;

Figure-7 iscan enlarged fragmentary perspective view of the inner end ofthe push rod; and

Figure 8 is a perspectiveiview of the guard wheel.

Referringto the drawings inqdetail, a combination lock designatedgenerally 10 and generally of the type disclosed in prior United :StatesPatent No. 1,956,304; issued April 20;:1934, to Abbottand Miller,comprises a housing having-'aiback cover plate .12 and an opening14'through which a locking bolt-:16iis mounted to move in a rectilinear,path from "311 active position in which it is pro jected; asillustratedrin Figure 2, to an inactive position inr which hisretracted; as illustrated in Figure 5. Mounted for'rotation about atubular bearing 18 carried bythe housing;are,tumbler. wheels .20 whichare providedrxwith peripheral notches 22' for the'reception of the.

fence bar" of the lock when the combination has been properlyi'set up;Thestructure so far defined-is conventional with combination-locks ofthe type to which this invention relates and :fo'rmsy no part-of theinvention except in com'bination' therewith;

Mounted iforsrotation -about a common axis which extends through thetubular bearing-718 B a tubular spindle 24-carryingradjacentritsouterend a lock operating knob 26 and;a;dial 28;: bothrof Jconventional form,it being understoodthat the; dial cooperates with 'a dial plate.lid-carrie'd'byadoorrD upon;whih the lock is mounted; Carried ibyc-theknoba 26% :and- E dial;28; and extending axially through; the: spindle:24 in alignment with: the common axis' and:for: rotationzwiththespindle: 24is' a-, push rod 32 which extends through a recess 34formed in theouter end 2 of: the '2 knob r26 T lI1T axial 1 alignmentwith-:the :spindle 24! A push zbutton- 343 is=-carriedl by; the push rod32 anddnterposedsbetweenr-thebottom-of the recess 34 and the inner end,of thepushrbutton -36 is a compression coil spring, 38'rwhich; as'wi1l;be;readily understood upon referenee to the;dra-wings; tends-ltoiurge the push button 36' outwardly:- ofthe recess-34.. Extendingtransversely through'the: spindle24 ;and:opening through the end thereof.remote -from-the; knob 26 is s-a slot-4i) which opensthrough-the:end;ofthe;spindle 24=remote from the knob 26; Carriedbytthepushcrod: 32 remote froma the push buttonw36 'andextendingtransversely through the slot 40- isra cross-bar42vhaving recesses44-opening1through opposite endsythereof which-cross barextends throughthe slot. 40 in order to establish driving: connection bfilIW66l1 thespindle 24 and the push-rod 32; while permitting longitudinalmovementiof;th-e-push rod relative to the spindle.

Threadedly engaged with the spindle 24- adjacent theendthereof rernotefrom' the knob 26 .is a cam disk 44 havingmaurecess 46textending:therethrough: and opening common axisjeabout.whichrthertumbler wheels'20 and cam-disk 44 rotates Lisanoperating. lever 48 carrying. a camfollower; tongue 50 v whiclnentersthe slot 46' and establishes;operative. connection between the. cam 46 and bo1t.16 toflcause the bolt16 'tobe .retractedupon rotation of the knob 26 when the propercombination has FatentedfNom. 8; 1955' been arrived at. The cam followertongue 50 is advanced toward the cam disk 44 under yielding pressureexerted by a torsion spring 52, one leg of which is anchored in the bolt16, while the opposite leg bears on the operating lever 48. Carried bythe operating lever 48 and extending transversely across the peripheriesof the tumbler wheels 29 is a fence 54 which in the preferred form ofthe invention is provided on its underside with serrations 56.

A guard wheel designated generally 58 comprises a disk 60 having anaxial opening extending therethrough for the reception of the spindle24, and carried by said disk 60 and extending outwardly therefrom inconcentric spaced relation to the axis thereof is a hub 62 having atransverse slot 65 extending therethrough for the reception of the crossbar 42 to establish rotary driving connection between the spindle 24 andthe guard wheel 58. In order to move the guard wheel 58 longitudinallyin unison with the push rod 32, the hub 62 is provided with an annulargroove 64 which is adapted to register with the notches 44 to receive aspring ring 66 by which the guard wheel 58 is coupled to the push rod 32for longitudinal movement therewith. Carried by the disk 60 andextending around the periphery thereof is a coneshaped guard rim 68which projects laterally from the disk 60 on the side thereof remotefrom the hub 62 and is adapted to encircle the periphery of the cam disk44 previously referred to. It is to be noted that the guard rim 68diminishes in diameter as it recedes from the outer side of the disk 60so that it may enter between the periphery of the cam disk and the camfollower tongue 58 under the influence of the spring 38 to move the camfollower tongue out of contact with the periphery of the cam disk duringthe manipulation of the lock. with a beveled edge 7-9 which cooperateswith the thin edge of the guard rirn 68 in forcing the operating lever48 to move against the effort of the spring 52 under the influence ofthe spring 38. Extending through the disk 60 between the hub 62 and rim68 is an arcuate slot 72 which accommodates an actuating pin 74 whichprojects outwardly from the cam disk 44 for engaging the lock boltprojecting tongue 76 carried by the operating lever 48.

In the preferred form of the invention, the cover plate 12 is providedwith a chamber 78 which aligns axially with the spindle 24 for theaccommodation of the guard wheel 58 when the latter is moved under theinfluence of the push rod 32 to its inactive position out of theencircling relation to the cam disk 44 and carried by the back wall ofthe chamber 78 is a guard pin 80 which prevents the entrance of theguard wheel 58 into the chamber except when the slot 72 is inregistration with the pin 80. Owing to the fact that the slot 72 extendsonly for a portion of the distance equal to about 90 of the periphery ofthe guard disk, it is evident that the guard disk cannot be moved underthe influence of the push button 36 except when the slot 72 thereinregisters with the guard pin 80, and obviously engagement of the guardpin 80 with opposite ends of the slot 72 will limit the magnitude ofrotation of the guard wheel to only that required for moving the bolt16.

In use, it will be evident that upon turning the knob 26, the spindle 24will be rotated and one knowing the combination will employ the dialplate 28 and indices carried by the dial to move the tumbler wheels 20so that the slots 22 therein will register beneath the fence 54, then byturning the cam disk 44 into a position to register the recess 46therein with the cam follower tongue 50, it will be evident that upondepressing the push button 36 against the effort of the spring 38, theguard wheel 58 will be moved into the chamber 78 to remove the guard rim68 from its position between the cam follower tongue and the cam disk44, thus enabling the arm 48 to move under the influence of the The camfollower tongue is preferably provided spring 52 toward the axis of thespindle 24 and the fence 54 into the recesses or notches 22 in thetumbler wheels 20. As the cam follower tongue 50 enters the recess 46 inthe cam wheel 44, it will be evident that upon rotating the spindle 24in a counterclockwise direction when viewed in Figure 2, the bolt 16will be retracted. When it is desired to restore the lock to lockedposition, the spindle 24 is rotated in a clockwise direction when viewedin Figure 2 to cause the pin 74 to engage the bolt actuating arm 76 tomove the lever 48 in a direction to project the bolt. As the arm 76 andtongue 58 move outwardly while the bolt 16 is being projected, the fence54 will be lifted out of the notches 22 in the tumbler wheels 20 into aposition substantially as illustrated in Figure 2, and as these elements76 and 50 move outwardly or away from the axis of the spindle 24 againstthe effort of the spring 52, the sharpened or thinner edge of the rim 68will enter between the periphery of the disk 44 and the cam followertongue 50 so that the cam follower tongue will ride on the guard rim 68when the spindle 24 is rotated in either direction. By thus interposingthe guard rim 68 between the cam follower tongue 50 and the periphery ofthe cam disk 44, it will be evident that detection of the passage of therecess 46 beneath the cam follower tongue will be avoided. Owing to thefact that it is necessary to register the slot '72 with the guard pin inorder to move the guard rim 68 clear of the cam disk 44, it will beevident that for the major portion of the operation, the guard disk 58will not respond when pressure is applied on the button 36 to disengagethe periphery of the cam disk. Moreover, during the period that the slot72 may register with the guard pin 80, unless the notches 22 in thetumbler wheels 20 align beneath the fence 54, the serrations 56 on thefence will, if the fence moves downwardly far enough to engage theperipheries of the tumbler wheels, mesh with the serrations on theperipheries on the tumbler wheels so as to frustrate any attempt on thepart of an unauthorized person to manipulate the lock and feel thepassage of the notches 22 beneath the fence.

From the foregoing, it will be evident that a manipulation-proof lock isprovided which will frustrate any attempt on the part of an authorizedperson to open the lock.

While in the foregoing there has been shown and described the preferredembodiment of this invention, it is to be understood that minor changesin the details of construction, combination and arrangement of parts maybe resorted to without departing from the spirit and scope of theinvention as claimed.

What is claimed is:

1. In a combination lock of the type comprising a bolt mounted to movein a rectilinear path, a cam disk mounted to rotate about a common axiswhich intersects and extends perpendicularly to the rectilinear path,said cam disk having a recess extending therethrough and opening throughthe periphery thereof, an operating lever carried by the bolt formovement in an arcuate path which intersects the common axis, and a camfollower tongue carried by the operating lever for engagement with theperiphery of the cam disk and advance into the recess therein to retractthe bolt upon rotation of the cam disk, means for preventing detectionof the passage of the recess beneath the cam follower tongue comprisinga rim guard mounted adjacent the cam disk for movement longitudinally ofthe common axis from an active position in which it encircles the camdisk and engages the cam follower tongue to an inactive position inwhich it lies to one side of the cam disk and out of the path of advanceof the cam follower tongue.

2. In a combination lock of the type comprising a bolt mounted to movein a rectilinear path, a cam disk mounted to rotate about a common axiswhich intersects and extends perpendicularly to the rectilinear path,said cam disk having a recess extending therethrough and opening throughthe periphery thereof, an operating lever carried by the bolt formovement in an arcuate path which intersects the common axis, a camfollower tongue carried by the operating lever for engagement with theperiphery of the cam disk and advance into the recess therein to retractthe bolt upon rotation of the cam disk, means for preventing detectionof the passage of the recess beneath the cam follower tongue compris'ing a push rod mounted in the lock for movement longitudinally along thecommon axis, an annular rim guard carried by the push rod for movementtherewith adjacent the cam disk from an active position in which itencricles the cam disk and engages the cam follower tongue to aninactive position in which it lies to one side of the cam disk and outof the path of advance of the cam follower tongue, and means carried bythe lock and operatively engaging the push rod for yieldingly advancingthe annular rim guard under yielding pressure into cam disk encirclingrelation.

3. In a combination lock of the type comprising a bolt mounted to movein a rectilinear path, a cam disk mounted to rotate about a common axiswhich intersects and extends perpendicularly to the rectilinear path,said cam disk having a recess extending therethrough and opening throughthe periphery thereof, an operating lever carried by the bolt formovement in an arcuate path which intersects the common axis, and a camfollower tongue carried by the operating lever for engagement with theperiphery of the cam disk and advance into the recess therein to retractthe bolt upon rotation of the cam disk, means for preventing detectionof the passage of the recess beneath the cam follower tongue comprisinga rim guard mounted adjacent the cam disk for movement longitudinally ofthe common axis from an active position in which it encircles the camdisk and engages the cam follower tongue to an inactive position inwhich it lies to one side of the cam disk and out of the path of advanceof the cam follower tongue, and means carried by the lock andoperatively engaging the rim guard for advancing the rim guard underyielding pressure into cam disk encircling position, and means operablefrom the front of the lock and operatively connected to the rim guardfor moving it against the yielding pressure out of the path of advanceof the cam follower tongue to permit said tongue to enter the recess inthe cam disk and operatively connect the operating lever to the cam diskfor movement of the bolt. k

4. In a combination lock of the type comprising a bolt mounted to movein a rectilinear path, a cam disk mounted to rotate about a common axiswhich intersects and extends perpendicularly to the rectilinear path,said cam disk having a recess extending therethrough and opening throughthe periphery thereof, an operating lever carried by the bolt formovement in an arcuate path which intersects the common axis, a camfollower tongue carried by the operating lever for engagement with theperiphery of the cam disk and advance into the recess therein to retractthe bolt upon rotation of the cam disk, means for preventing detectionof the passage of the recess beneath the cam follower tongue comprisinga rim guard mounted adjacent the cam disk for movement longitudinally ofthe common axis from an active position in which it encircles the camdisk and engages the cam follower tongue to an inactive position inwhich it lies to one side of the cam disk and out of the path of advanceof the cam follower tongue, means carried by the lock and operativelyengaging the rim guard for advancing the rim guard under yieldingpressure into cam disk encircling position, means operable from thefront of the lock and operatively connected to the rim guard for movingit against the yielding pressure out of the path of advance of the camfollower tongue to permit said tongue to enter the recess in the camdisk and operatively connect the operating lever to the cam disk formovement of the bolt, and the outer periphery of the annular rim guardbeing beveled to facilitate the entrance thereof between the cam diskand the cam follower tongue.

5. In a combination lock of the type comprising a bolt 5 mounted to movein a rectilinear path, a cam disk mounted to rotate about a common axiswhich intersects and extends perpendicularly to the rectilinear path,said cam disk having a recess extending therethrough and opening throughthe periphery thereof, an operating lever 10 carried by the bolt formovement in an arcuate path which intersects the common axis, and a camfollower tongue carried by the operating lever for engagement with theperiphery of the cam disk and advance into the recess therein to retractthe bolt upon rotation of the cam disk, means for frustrating theunlocking of the lock by detection of the passage of the recess beneaththe cam follower tongue comprising a rim guard mounted adjacent the camdisk for movement longitudinally of the common axis from an activeposition in which it encircles the cam disk and engages the cam followertongue to an inactive position in which it lies to one side of the camdisk and out of the path of advance of the cam follower tongue, said rimguard having a slot extending therethrough in spaced concentric relationto the common axis, and a pin carried by the lock and projectingoutwardly therefrom and into the path of the rim guard for entrance intothe slot when the rim guard is moved out of the path of advance of thecam follower tongue.

6. In a combination lock of the type having a bolt mounted to move in arectilinear path, tumbler wheels and a cam disk mounted to rotate abouta common axis which intersects and extends perpendicularly to the rectilinear path, the peripheries of the tumbler wheels being serrated andhaving fence receiving notches opening thereinto, said cam disk having arecess extending therethrough and opening through the periphery thereof,an operating lever carried by the bolt for movement in an arcuate pathwhich intersects the common axis, a cam follower tongue carried by theoperating lever for engagement with the periphery of the cam disk andadvance into the recess therein to retract the bolt upon rotation of thecam disk, a fence carried by the operating lever and extending acrossthe tumbler wheels for entrance into the notches therein when the camfollower tongue enters the recess in the cam disk, means for preventingdetection of the passage of a notch beneath the fence and the passage ofthe recess in the cam disk beneath the follower tongue, said meanscomprising a rim guard mounted to move longitudinally along thelongitudinal axis from an active position in which it encircles the camdisk and engages the cam follower tongue to hold it out of contact withthe cam disk to an inactive position in which it lies to one side of thecam disk and out of the path of advance of the cam follower tongue,means carried by the lock and operatively engaging the rim guard foradvancing it under yielding pressure into active position, manuallyactuated means carried by the rim guard and extending through the lockfor moving the rim guard against the yielding pressure to inactiveposition adjacent the cam disk to allow the fence to advance intocontact with the tumbler wheels, and spaced parallel serrations carriedby the fence and extending parallel with the common axis for meshingengagement with the serrations on the tumbler wheels and frustrating thedetection of the passage of a notch beneath the fence.

References Cited in the file of this patent UNITED STATES PATENTS O 794,156 Weimar Aug. 24, 1869 237,950 Bernhardt Feb. 22, 1881 821,548Streeter et a1 May 22, 1906 2,575,674 Miller Nov. 20, 1951

